鎘對毛豆幼苗之影響

Effects of Cadmium on Soybean Seedlings

毛豆幼苗葉片於鎘處理後10日分析之。結果顯示毛豆葉片之呼吸作用率，蘋果酸鹽去氫酶，酸性磷酸酯酶，核糖核酸酶。去氧核糖核酸酶及過氧化酶等之活性顯著增高。碳酸酐酶活性減低。水解酶及過氧化物酶活之增加似為處理後毛豆衰老之反應。碳酸酐活性減低，或係由於鎘取代內含鋅之結果。高濃度（1.35μM）鎘處理，促進毛豆葉片黃化，捲曲（epinasty），離層發生之生長減少。

Soybean (Glycine max Merr. cv. Columbus) seedlings grown in culture solution were treated with cadmium as CdSO4. Final concentrations of cadmium (Cd(superscript 2+)) in the solution were 0, 0.45, 0.90, and 1.35μM, Soybean leaves, analyzed 10 days after Ca(superscript 2+) was added to the culture solution, showed increased respiration rate and activities of malate dehydrogenase, acid phosphatase, ribonuclease, deoxyribonuclease, and peroxidase but decreased activity of carbonic anhydrase. Increased activity of hydrolytic enzymes and peroxidase reflects a general senescence response while the carbonic anhydrase decrease is consistent with an antagonism between cadmium and endogenous zinc. Chlorosis, epinasty, abscission of leaves, and decreased growth rate occurred in seedlings treated with 1.35μm Cd(superscript 2+).